Spectacle sighting device



Feb. 22, 1949.

vFiled Sept. 13, 1945 K. CLARK Erm. 2,462,468 SPECTACLE SIGHTING4 DEVICE i 3 Sheets-Sheet 1 la? 135 u la? Maly Feb. 22, 1949. K. CLARK ET AL SPECTACLE SIGHTING DEVICE 3` Sheets-Sheenl 2 Filed Sept. 13, 1945 `JNVENTOR. fri/fende C/Qrk Feb. 22, 1949. K CLARK ET AL 2,462,468

SPECTACLE S IGHTING DEVICE Filed Sept. 15, 1945 3 Sheets-Sheet 3 l'5" as? /57- l 5 7 j 9 A INVETOR. 4 was FIG /fmm/ Var/f BY fnneT/f 0. Sfssafz Patented Feb. 22, 1949 2,462,46&

SPECTACLE SIGHTING DEVICE Kendall Clark and Kenneth 0. Sisson, Oakwood, Ohio, assignors to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application September 13, 1945, Serial No. 616,134

2 Claims.

This invention in one of its applications relates to a spectacle sighting device which may be used on aeroplanes or elsewhere.

Sighting devices have been used to determine the location of ships, aeroplanes and other vehicles. They are also used for air bombing and the direction of gun iire. Most of these sighting devices when in use require the entire attention `of the operator and the use of both hands for a. continuous vperiod of considerable length. Many are extremely complicated.

It is an object of our invention to provide a sighting device for air bombing and other purposes which requires less attention and particularly requiresv attention only for short periods of time when actually sighting.

It is another object of our invention to provide a sighting device which leaves both hands free during bombing and other sighting.

It is another object of our invention to provide a sighting device which may be used while piloting a plane.

I It is another object of our invention to provide an extremely simple, light Weight sighting device which is suiiciently accurate for low altitude `bombing and which may be readily adjusted to provide various sighting angles.

It is still another object of our invention to provide a sighting device attached to a pair of spectacles to allow wide angle vision and in which the sighting line is pre-set and does not require sighting upon the target excepting for an instant while making a bombing run or other observation.

Briefly, to attain these objects we provide a pair of adjustable spectacles which can be readily adjusted to properly t the eyes of any person. Pivotally connected to the spectacles is an illuminated ball type level indicator. Also connected to the spectacles is a focusing lens covering slightpanying drawings, wherein a preferred form of Athe present invention is clearly shown.

In the drawings: Fig. 1 is a front view of our sighting devic 'including the adjustable spectacles.;

Fig. 2 is a sectional View taken along the line 2-2 of Fig. 1;

Fig. 3 is a side view of the device shown in Fig. 1 with portions of the spectacles shown in dot and dash lines;

Fig. 4 is a sectional view, partly diagrammatic, showing the level indicator, the'reilectors and the lens;

Fig. 5 is a sectional view taken along the line 5 5 of Fig. 1 with the device set for sighting i it is not held level.

Referring now to the drawings, there is shown a pair of spectacles 20 including the eyeglasses 22 and 24 supported within the rims 26 and 28. The rim 26 is provided with a bracket 30. This bracket 30 carries a shaft 18 (Fig. 3) provided with a mirror 32 at one end which over-hangs the bracket 30 so that the mirror is located beneath the level oi the eye adjacent the bottom portion of the eyeglass 22. On the shaft 18 between the arm 34 and the ear 36 of the bracket 30 there is provided a hub 38 which is xed to the lever 40. This hub 38 is rotatably mounted upon the shaft but it can be held in any adjustable position by the knurled linger nut 42 which is threaded onto the end of the shaft 18 for clamping the hub 38 and lever 4B between the arm 34 and the ear 36. This knurled nut 42, when tightened, tightens the shaft 18 and holds the hub 3B, the lever 40 as Well as the mirror 32 in a iixed relationship to the spectacles.

At its lower end the lever 40 carries a clamping block 44. This clamping block 44 is threaded so as to receive the threaded ball housing 4S of the 'illuminated level indicator 48. The threaded ball housing 4B at its upper portion is recessed to support a disc-shaped ball seatvll preferably of glass or some similar transparent material having a concave spherical upper surface and a plane frosted lower surface. A polished steel ball 52 rests on the spherical surface and is.. surrounded by. a ring-shaped ball rethe eye.

tainer 54 having a concentric aperture therein slightly larger than the maximum diameter of the ball 52. This ball retainer 54 may be silvered on its bottom face and on the inside of the aperture so that no light may pass through it. Spaced by a seal ring from the ball retainer 54 and the ball 52 is the ball cover 58 in the orm of a plane polishedtransparent glass disc. The chamber containing :thevball 52 is filled with a light oil and sealed by the spacer rings provided on either side of the glass disc-shaped members 55, 54 and 58 within the ball housing 48. A .cap 68 lits tightlyY on the top of the ball housin'gf`48 and holds the members 58,?5l1and .58 :in place.

The ball housing 48 is provided with a lowerV chamber 6i containing a light bulb 82 .provided with an integral lens. The light. .bulb illuminates the ball and ball chamber and since the Lball and ball retainer are opaque, the space between `.the ball 52 and the edges of the aperture in the ball retainer `will be brilliantly :illuminated while :the remainder is dark. If the ball is exactly in a concentric-position it indicates that the axis of theindicator assembly is exactly vertical. YIt will be readily apparent, if the ballY is not con-- centric with the aperture, since there will be no uni-form ringof light around the ball. It has been found that the eye is particularly sensitive to this arrangement and .-it is very .easy for. most persons to hold the indicator so that its axis is truly vertical. The bulb S2 is threaded into a -metal socket 8d provided witha terminal con- 'nectedr to theeconducter 88. This socket .is supported in the bulb socketcap `88 of insulating material which carries the center Contact mem- .ber 18 connected to the conductor 12. The center contact oi the light .bulb 'E2 contacts this center contact 18.

The mirror 32 is supported directly overthe ball 52 by the bracket 38. The enlarged end of the shaft 18 carrying the mirror 32 is provided with a key projection 14 keyed to a slotted lever 16 which therefore rotates with the mirror and the shaft 18. A link 88 is pivotally connected to the bracket 38 byzthe lrivet 82. A second link 84 of equal length is pivoted to the lever 48 by the rivet 86. The lower ends of these two links 88 and 84 are connected by a pin 88 which rides `in the .slot 90 in the lever 18. It should be noted that the two equal length links84 and 88 serve to keep the slotted lever 18 exactly equally spaced between their rivets V82 and 88 no matter what the .distance is between `these rivets.

VThe extreme end of the'arm '34 carries a semi- `circular mirror 92 which is mounted upon a stud f94' fastened to the arm by the nutf98. Thismirror 92 is mounted directly in front of a similarly shaped convex zlens 98 which is fastened to the eyeglass 22 Aso that its axis is directly in front of The cut-:oil part of `its circle permits 'some vision ofthe eye past the lens 98 :and the mirror 92. The level indicator 48 isthrea-ded up ordown within *the clamping 'block '44 until 'the ball is brought exactly in the focal .-p'oint ofthe ...lens '88. The clamping screw |,2I is then'tightindicator may be'pivoted on vthe axis of the shaft A18 to any desired angle within the 'limit .of about `90 degrees. InFig. `5 the leverll ispositionedto Ahold the llevel indicator exactly 'vertical'providfing an exactly .horizontallineof vrsight from `the eye |23 through the lens 98 to the .mirror 92. In

The amount of angular movement of the mirror 32 required to -do this is just half the amount of Vrelative movement between the eyeglass 22 and the vrlevel .indicator 48. Iment is .provided .automatically by the equal This amount of movelength links 88 and 84, together with the slotted lever 16. When the eyeglass 22 was moved relative to the level Vindicator through an angle of 60 degrees in changing the setting from that shown in Fig. 5 to that shown in Fig. 6, the slotted lever 16 and .the mirror 32 was automatically rotated through .an angle of degrees. Through this simple arrangement the line of sight from the eye |23 through the lens 98 to the mirror .92, thence to the mirror 32, thence to the ball 52 and the level indicator 4.8, is always preserved automatically no matter .what the angular adjustment may be.

To make it possible for dinerent vpersons to use the sight without changing spectacles, .the spectacles are made adjustable. For thispurpose the top `of the rim 28 has fastened to it .a rod-|21 y which threads through the ears |28 and |3| extending from the top of the rim '26. vA thumb screw |33 is threaded onto lthe end .of the rod |21 and may be adjusted to move the eyeglass 22 toward or away `from the eyeglass 24. A light coil spring 35 is. threaded onto the shaft |21 .between the ear |29 anda nose supporting block |31. This keeps the ear |3| against the thumb screw |33 in all positions of adjustment. The ear |`5| carries a slide rod |53 which slides through an .aperture in the ear |58 to keepthe eyeglasses -22 and 24 in alignment. YThe nose Vsupporting Vblock .|31 .is zapertured from top Ato bottom to receive 1.a threaded shaft |4| .which is adjusted by a thumb nut |39 which is lodged in a horizontal slot provided in the nosea'djusting block |31. 4The bottom of this threaded shaft |4| is fastened .to .a yoke |43 carrying the nose pads .|45 and |41. By

.this arrangement the thumb screw v|39 maybe turned .to vraise or lower `,the Anose pads..|45 .and |41 relative -to the eyeglass 22 and :24 .and the lens 98 so that the lens 98 can be positioned directly -on the same horizontal level as the -,eye .while the thumb screw |33 .can be adjusted =.to .per-

.plain if the wearer needs no optical correction for normal vision. `The .eye .which looks Vthrough the vglass24 then has free vision of .any sighting .ob- VYjective vor vbombing target.

.In the other eye, which looks through .the glass .22, .two images are superimposed. As shown in...Fig. 7,.-the eye |23 receives the light-rays in ring-.shaped ,pattern which emanatev from the .level indicator 48 (Fig. .4l .and are .reflected .by the .mirrors .32 .and..9`2 and are `then .collimated by the .lens ..98 whichis a convex collimating .-lens. The collimating lens 98, which covers about 60% of-theeye, transmits only .parallel rays `oflight tothe eye |23. 'This makes the apparentimage |151 of `the-ring-o'flight appear Ias if it were xed upon an object in the distance, for example, a ship |59. The object in the distance, such as for example, the ship |59, is viewed alongside the cut-away portions of the lens 98 and the mirror 92, as indicated by the heavy dotted line in Fig. 7. This vcauses the apparent image |51 of the ring of light to appear as if it were superimposed upon the object, such as the ship |59, as shown in Figs. 8 and 9. A1- though part of the lens 98 and the mirror 92 is cut away, nevertheless, a complete ring image is form-ed in the eye due to the inherent properties of the convex lens. This will determine the direction of view of both eyes relative to the level indicator 48 and when the head of the wearer an-d the spectacles are so positioned as to hold the ball 52 directly in the center of the aperture of the ball retainer 54 the axis of the level indicator 48 will be exactly vertical and the line of sight will be accurately determined. As long as the wearer of the spectacles holds the level indicator directly vertical and keeps la portion of the vision of one eye directed onto the illuminated ring surrounding the ball 52, while keeping the eyes searching for the target, the bomb may be released when the target comes directly into the field of vision. If the angle has been properly set the bomb will strike the target.

The wearer of the spectacles, however, is free to turn his eyes in other directions at any time and can turn his head freely to look .in other directions. He can pilot a plane or perform other duties. It is only necessary at the exact instant of sighting to have the light ring around the ball concentric and to View both the light ring surrounding the ball 52 and the target or object of sighting to use the sighting device. Both hands are always free except when adjusting the sighting device to the desired angular position. Furthermore, the head is much more stable than the hands and naturally compensates for the movement of the remainder of the body, such as would occur in the rolling of a ship or the bouncing of a plane. For this reason the head can hold the spectacle sighting device much more steady than a hand-held sighting device, thereby providing a natural inherent stabilization.

Fig. 7 is a diagrammatic view illustrating certain optical principles embodied in the device and inherent in its use;

Fig. 8 is a View of the apparent image of the level indicator when level superimposed on an object; and

Fig. 9 is a view of the apparent image of the level indicator when not level superimposed on an object.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

l. A sighting device for sighting at various measurable angles relative to the vertical including spectacles adapted to rest upon the nose, one of the eyepieces of the spectacles being provided with a small segmental collimating lens positioncd so that the vision is split and the lens .is in the path of a substantial portion of the directly forward vision field of one eye but leaves a substantial portion of the directly forward vision eld free of the lens, the spectacles having a forwardly extending bracket, mirror means mounted upon said bracket and having a portion located directly in front of said collimating lens, a level indicating means pivotally mounted upon sai-:i bracket, means connecting the bracket and the level indicating means with the mirror means to move the mirror means to reect light from the level indicating means to the collimating lens.

2. A sighting device for sightinT at `various measurable angles relative to the vertical :including spectacles adapted to rest upon the nose, one ci "se eyepieces of the spectacles being provided with small segmental collimating lens positicned so that the vision is split and the lens is in the path of a substantial portion of the direc:- ly forward vision eld of one eye but leaves a substantial portion of the directly forward vision eld free of the lens, the spectacles having a forwardly extending bracket with a forwardly extending arm, a rst mirror positioned in front of and in the path of rays collected by the collimating lens and being mounted upon said arn said mirror being restricted in area so it will not obstruct the free eld of vision, a second arm pivoted to said bracket, .1. level indicator fixed to said second arm, a second mirror pivotally mounted upon said bracket, means connecting said second arm and said bracket with said mirror for moving the second mirror as the second arm is pivoted relative to the bracket for reflecting rays from the level indicator to the rst mirror, said nrst mirror being positioned at the angle required to reflect the rays from the second mirror to the collimating lens.

KENDALL CLARK. KENNETH O. SISSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 353,406 Gurley Nov. 30, 1886 444,495 Johnston Jan. 13, 1891 1,851,579 I-Iixon Mar. 29, 1932 1,877,459 Hayes Sept. 13, 1932 2,088,597 Hegenberger et al. Aug. 3, 1937 2,316,466 Storer Apr. 13, 1943 2,352,644 Linderman, Jr., et al. July 4, 1944 2,389,428 Glasser Nov. 20, 1945 2,410,667 Luboshez Nov. 5, 1946 

